In short .. yes
You can attach ANY drawing regardless of name, to the xref already in a drawing. The layer state will remain the same. For example...
Xref sitelayout into your drawing.
Set your layerstate(s)
In the xref dialog, highlight sitelayout from the list, then select the browse button beside "found at" and select newsitelayout. The xref will be updated to the file you pointed to, but will remain named the same in the drawing.
You can now rename the xref with the rename block command in the drawing. It will update the layers from sitelayout|layername to newsitelayout|layername